Web System Scaling: Load Balancing, Caching, and Database Optimization Strategies

When a web system grows from 100,000 daily visits to 100 million or more, the pressure on the architecture increases dramatically, requiring multi‑level caching and load‑balancing solutions at different stages.

Load Balancing Strategies include simple HTTP redirection, reverse‑proxy load balancing (e.g., Nginx), IP‑level load balancing with LVS, DNS load balancing, and DNS/GSLB combined with CDN to route users to the nearest server.

Web System Caching Mechanisms start with MySQL internal caches (proper indexing, thread cache, innodb_buffer_pool_size, sharding), then move to multi‑server MySQL deployments (master‑slave, read‑write separation, master‑master), and finally to caching between web servers and databases using page static‑generation, single‑node memory caches (Redis/Memcached), and memory‑cache clusters such as Redis Cluster.

Additional techniques include reducing database writes by batching updates, using NoSQL key‑value stores (Redis) for hot data, and handling empty‑node queries with mapping tables stored in memory caches.

Geographic Deployment follows the principle of a centralized core with distributed nodes, using DNS/GSLB to direct traffic, and ensuring node disaster recovery and overload protection through failover and traffic throttling.

The overall process shows that a web system evolves from a single server to a large distributed cluster by continuously solving new performance challenges, and that optimization has no upper bound as software and architecture keep advancing.